Joy stick controller for tower crane

ABSTRACT

Apparatus for controlling independent actions of a tower crane, including horizontal trolley travel along the boom track, rotation of the boom itself, and vertical travel of the lifting hook, with a lever, or joy stick, in such manner that the resulting movements are smooth, rapid, and reliably controlled. The lever returns to an origin, or dead center position when not under the influence of an external force.

finite titats Pattie [1 1 Qording 1 1 .101! STICK CGNTROLLER FOR TOWER(IRANE [75] Inventor:

[73] Assignee:

[22] Filed: Feb. 28, 1973 [21] Appl. No.: 336,587

[52] US. Cl 212/56, 74/471 XY, 212/1, 212/63 [51] llnt. Cl. 1866c 23/02[58] Field of earclr 212/561, 63; 74/471 XY [56] References Cited UNlTEDSTATES PATENTS 2,762,234 9/1956 Dodd 74/471 XY 2,828,872 4/1958 Mange]212/63 X 3,076,559 2/1963 Crile 212/56 3,095,754 7/1963 Mayon et a1.74/471 XY Eldon F. Ion-ding, Galena, Ill.

Heede international, lnc., Greenwich, Conn.

[ Mar. 11., 1975 Leonard et a1 74/471 XY 3,299,731 1/1967 Russell3,365,975 l/l968 Hathaway 74/471 XY 11/1970 Pool et a1 74/471 XY XPrimary ExaminerEvon C. Blunk Assistant Examiner-.ieffrey V. NaseAttorney, Agent, or Firm-Jackson, Jackson & Chovanes [57] ABSTRACTApparatus for controlling independent actions of a tower crane,including horizontal trolley travel along the boom track, rotation ofthe boom itself, and vertical travel of the lifting hook, with a lever,or joy stick, in such manner that the resulting movements are smooth,rapid, and-reliably controlled. The lever returns to an origin, or deadcenter position when not under the influence of an external force.

2 Claims, 9 Drawing Figures PATENTEU 1 I975 SHLU 1 UP 4 FIG. I

.IOY STICK CONTROLLER FOR TOWER CRANE BACKGROUND OF INVENTIONConstruction tower cranes including those of the climbing type haveessentially a vertical or mast position and a horizontal boom positionwhich in cantilever manner extends from the mast and rotates thereon. Atrolley rides horizontally on the boom which can be, for instance, up to200 feet in length. A dependent cable extends from the trolley and hasattachment means for lifting the load.

An operator located in a cabin within the mast or slightly below theboom controls the swing of the boom, the radial position of the trolleyon the boom, and the lift of the cable.

In most prior art tower cranes, to control the swing of the crane, thetrolley position and the hook position, the operator manipulatedindividual levers, mechanisms or switches. For instance, the operatorwould shift a lever to control the swing of the boom with his left handand would move another lever to control the trolley on the boom, withhis right hand. He would use still other pedals or levers to raise andlower the hook. The ultimate concern of the operator was to position theload being moved by the crane in a most efficient, direct, and safemanner. In many instances, the operator, to compensate for momentumproblems created by the huge weights being moved, including the load,and crane components, had to keep movements at relatively low speeds.Also, he was performing the lever and pedal operations individually andthis further complicated his tasks.

Efforts were made to combine control of the various crane movements intoa single lever device of the type used on planes and referred to as joysticks. Such prior art joy sticks developed as a result of these effortswere extremely bulky and in many instances occupied so much of the cabinspace that they were impractical.

SUMMARY OF THE INVENTION I The present invention is concerned with acompact and reliable apparatus for crane control having a single levermechanism or joy stick for reliably performing complete control of twoof the cranes actions. By the use of two lever mechanisms, one for eachhand of the operator, the crane can be fully controlled.

The vertical or Y-Y position on the coordinate axis through which thelever moves may be used, for instance, to control boom swing, and thetransverse'direction, the XX direction, may be used to control trolleyposition on the boom track. Another lever may be used for the liftcable, and in the case of travelling cranes, for mast travel. The leveris universally pivoted and movement of the lever is transmitted bypinion drive to potentiometers which transmit electrical signals toposition motors, or servo mechanisms. Additionally, lever movementactivates throttling action for suitably braking individual cranemovements. The joy stick may be moved freely over the entire length ofits operation without necessarily passing through dead center or zerocoordinate position. Additionally, the apparatus is a fail-safe system,since a release of force from the lever results in the actions beingcontrolled by such lever coming to a halt.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a towercrane involved in the present invention.

FIG. 1a is a perspective view, partly in phantom, showing the device ofthe invention.

FIG. 2 is an elevational view of the yoke trunion, gear drive andpotentiometer of the invention.

FIG. 3 is a view taken on the line 3-3 of FIG. 2.

FIG. 4 is an elevational view of a straight trunion in the assembly ofFIG. 1.

FIG. 5 is a view taken on the line 55 of FIG. 4.

FIG. 6 is a partial elevational view of the cam assembly.

FIG. 7 is a hydraulic circuit diagram. FIG. 8 is a schematic sketchshowing coordinate positions.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, a tower crane 10 hasa mast I 1 and a boom 12 which is supported in a cantilevered mannerfrom the mast. Mast 11 may be supported from the ground, or othersurface 13 and may be of the climbing type wherein sections are added asthe need arises. Boom 12 rotates, clockwise or counterclockwise, aboutthe mast. A track 14 of any suitable type has riding thereon a trolley15, having wheels which ride the track. A lift cable 17 depends fromtrolley I5.

A trolley cable drive drum I8 driven by a suitable motor, has woundthereon a trolley cable 19. One end of cable 19 extends along mast 11 toand over a suitable change of direction pulley located at the radiallyoutward end of boom 22. The cable is then attached to the trolley 15.

It will be seen that as drum 18 is rotated selectively in either aclockwise or counterclockwise direction, the trolley will be movedeither inwardly or outwardly along the boom. An operator within a cabinin the mast at 16 controls the swing of the boom. An operator within acabin in the, mast at 16 controls the swing of the boom, the trolleyposition on the boom track, and the movement of liftcable 17 from withinthe cabin. These features are all conventional and well known in theprior art.

The joy stick controller of the present-invention controls the swing ofthe boom, the trolley position on the boom track, and the movement oflift cable.

Referring to the drawings I show the device of the invention having ahousing 20 with sides 21, 22, 23 and 25. The housing is open at the topand bottom. Extending across from sides 22 to 25 in the housing, is atrunnion 26 journalled at 27 and 28. The trunnion 26 has an open channelportion 30 as best seen in FIGS. I and 5. Fixed transversely within saidchannel 30 is a shaft 31 having journalled thereon sleeve 32 of lever 33having knob 35. Knob 35, lever 33, and sleeve 32 are integral, and arefree to rotate about shaft 31. Channel 30 has sides wide enough torestrain or guide sleeve 32 during such rotation.

Lever 33 extends upwardly through a slot 36 on curved yoke 37, suitablyjoined as by welding, to trunnion blocks 38 and 4%. Blocks 38 and 40have extending therefrom pivots I1 and 42 journalled in housing sides 21and 23 respectively. Extending from trunnion blocks 40 and fixed theretois gear segment 43 as best seen in FIGS. 2 and 3. Such gear segment 43has gear teeth 45 extending over approximately a 90 arc. Gear teeth 45mesh with pinion 46 having hub 50 fixed on shaft 47 joumalled inside 21of housing 20. The shaft 47 extends through side 21 through a suitablesleeve and has fixed thereon at the outside a standard, conventionaltype potentiometer 44. Such potentiometer is of a type having around a340 rotation. Suitable leads from the potentiometer connect with a motordrive for a variable speed hydraulic drive pump.

A gear segment 51 identical to the gear segment 43, is fixed to trunnion26 at 54. Segment 51 has teeth 52 which engage with a pinion 53journalled on a shaft extending through side 25, and having fixedthereon a potentiometer identical to potentiometer 44, having suitableoutput leads. The gear segment and pinion and potentiometer arrangementon trunnion 26 is identical as that described and shown in FlGS. 2 and3, and will be referred to when necessary by primes on the correspondingnumbers.

Fixed -on shaft 57 extending from trunnion 26 is crank arm 58 having atits end roller cam 60. Cam followers 61 and 62 pivoted at 63 and 65engage roller cam 60. Stops 66 and 67 fixed on side 22 prevent downwardmovement of cam followers 61 and 62 against the bias of helically woundtension springs 68 and 70, respectively, anchored at posts 71 and 72 onthe housing, and 73 and 75 on the cam followers. Extension arms 76 and77 are fixed on cam followers 61 and 62 and 78 and 80. Bearing faces 81and 82 are formed on arms 76 and 77 which selectively depress therespective contact buttons of miniswitches 83 and A duplicate set ofroller cam, followers, switches and related parts are mounted on theoutside of side 23 and are fixed on the shaft extension of trunnion 26.Such duplicate parts are designated by the same numbers primed wherenecessary. This duplicate arrangement is connected to trunnion block 38.

Suitable mounting blocks 85 are fixed on housing 20, wherein the housingcan be bolted, or otherwise affixed on the operators control desk orother suitable location.

In FIG. 7 I show therein a variable displacement reversing pump 114 ofthe conventional type which is driven by a constant speed electricmotor. Pump'l14 can be controlled to vary output and direction by meansof a corresponding electrical signal transmitted through electricalleads from a potentiometer on the lever assembly described above. Thepump 114 has connecting lines 115 and 116 in a hydraulic loop whichconnect with lines 106 and 117. Line 117 connects with a hydraulicallydriven motor 105, as does line 106. Motor 105 drives one of the cranemovements, for instance the boom rotation. Line 104 connects with line115 and line 118 connects with lines 106 and 116. A connecting line 120and a connecting line 121 connect lines 118 and 104. Check valve 108 isinstalled in line 120 and check valve 103 is installed in line 121. Line122 connects with four-way valve 101. Check valve 107 is installed inline 122 and bypass line 123 bypasses check valve 107. A throttlingorifice, or a restrictive orifice 124, is installed in bypass line 123.Line 125 connects valve 121 to lines 120 and 121. Line 126 connectsvalve 101 to lines 118 and 120. Bypass line 127 is installed aroundcheck valve 102 installed in line 122. Pressure release valves 130 and131 are installed in lines 126 and 122. The relief valves empty intoreservoirs 132.

Reference will be made to FIG. 8 to aid in an explanation of theoperation. Such figure represents a plan view, that is, looking downwardon the device from above, with lever 33 movement related to coordinateaxes.

In operation, the device is connected to the crane operating controls sothat movement of the stick in one direction, for instance YY, willcontrol for instance the swing of the crane boom, and movement in an XXdirection will control trolley travel inwardly and outwardly along thetrack. The stick position will normally be at the origin or dead centerdesignated zero in FIG. 8. The stick will revert and maintain itself insuch position when no biasing force by the operator is exerted, underthe influence of the cam follower and roller cam arrangement at the endof each of the trunnions 26 and 38. Describing the operation of the camfollower and roller cam arrangement on 26, helical springs 68 and biascam followers 61 and 62 in a downward position. The follower contour ofthe cam followers as best seen in FIG. 6 has an inclined surface and anabruptly curving face 91. The abruptly curving face 91 corresponds incurvature to roller cam 60 curvature so that the roller cam 60 will becradled between the curvature 91 of each of the cams followers 61 and62. If a movement is madein an X direction the roller cam 60 will moveagainst cam 62 against the influence of spring 70. Cam follower 61 willbe retained in position by stop 66, when not in contact with roller cam60. If for instance the operator releases the force on lever 33, helicalspring 70 will exert a downward force on cam follower 62 forcing rollercam 60 back to its zero position or dead center position, along inclinedsurface 90 and then into curved surface 91 where the roller now becomescradled between followers 61 and 62. It will be seen from thisdescription that movement in the XX direction either toward X or Y willbe subsequently countermoved by the influence of the cam roller andsprings as described to an origin or dead center position when the leveris released. It will be seen that the lever 33 is free to move in an Xdirection and a Y direction simultaneously in the operation of thedevice. For instance, referring to FIG. 8 the lever can be taken fromits origin position 0 and moved out to a coordinate position designatedwhich would mean that the lever is moving in an X direction and a Y,direction simultaneously. This lever movement is shown by the path 96which represents a direct movement from 0 to 95. From position 95, theoperator is free to move to any other coordinate position to achieve thedesired crane control by direct movement. For instance, the operator canmove di rectly from '95 to 96 through path 97.

Alternatively, the operator could move within a quadrant itself, forinstance moving from 95 to 98 through path 99. The effect of thesemovements will be described later. It will be seen that the operatorthus has great flexibility in achieving positioning of the lever in aninfinitely variable number of positions without passing through anypredetermined path or lever operating direction.

The lever movement referred to above will be monitored by the mechanismincluding gear segments 43 and 52 and including the early referred togear and pinion arrangements and potentiometers. For instance,

movement of lever 33 in the direction from to origin to 95 results ingear segment 43 being rotated so as to drive pinion 46 andcorrespondingly potentiometer 44 through a number of degrees correspondto twice the degree movement of the lever, or twice the distance of thelever in that half direction. correspondingly, lever movement from 0 to95 will be translated in the X direction by the movement of the gearsegment 51, pinion 53, and potentiometer on trunnion 26. The output ofthese potentiometers will be determined by the amount of rotation of thepinions which in turn will rotate the movable arm of the potentiometer acorresponding number of degrees. The potentiometer will then transmit asignal corresponding to such degree of arm movement which in turncorresponds to the degree of lever movement. Thus, where there ismovement from the origin to for instance a 95, there will becorresponding signals transmitted both in the X direction and in the Y;direction.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

1. In a tower crane having a. a mast portion extending vertically; b. aboom portion extending horizontally from and rotating about the mastportion; c. a track on the boom having riding thereon a trold. a liftcable on the trolley and adapted to lift and lower crane loads; and e.separate driving means for rotating the boom, moving the trolley, andlifting and lower a load;

a lever pivoted on a pair of axes disposed normal to one another, meanson each of the axes for determining a signal proportional to levermovement, and means for transmitting the determined signals to theseparate driving means; wherein the lever is pivoted within a firsttrunnion, and said lever extends within a groove in a U-shaped portionof a second trunnion pivoted normally to said first trunnion, wherebysaid lever can selectively rotate both said first and second trunnionsseparately or simultaneously; said device having a gear segment fixed oneach of the first and second trunnions; a pinion engaged with each ofsaid segments, potentiometers adapted to be operated by rotation of saidpinions, whereby electrical signals proportional to lever movement aredetermined, and means for returning said lever to an origin, or deadcenter position, including a. cams on the first and second trunnions;

b. cam followers in engagement with the cams, and

c. springs biasing the cam followers against the cams.

2. The device of claim 1, wherein the driving means include fluid drivemeans.

1. In a tower crane having a. a mast portion extending vertically; b. a boom portion extending horizontally from and rotating about the mast portion; c. a track on the boom having riding thereon a trolley; d. a lift cable on the trolley and adapted to lift and lower crane loads; and e. separate driving means for rotating the boom, moving the trolley, and lifting and lower a load; a lever pivoted on a pair of axes disposed normal to one another, means on each of The axes for determining a signal proportional to lever movement, and means for transmitting the determined signals to the separate driving means; wherein the lever is pivoted within a first trunnion, and said lever extends within a groove in a U-shaped portion of a second trunnion pivoted normally to said first trunnion, whereby said lever can selectively rotate both said first and second trunnions separately or simultaneously; said device having a gear segment fixed on each of the first and second trunnions; a pinion engaged with each of said segments, potentiometers adapted to be operated by rotation of said pinions, whereby electrical signals proportional to lever movement are determined, and means for returning said lever to an origin, or dead center position, including a. cams on the first and second trunnions; b. cam followers in engagement with the cams, and c. springs biasing the cam followers against the cams.
 1. In a tower crane having a. a mast portion extending vertically; b. a boom portion extending horizontally from and rotating about the mast portion; c. a track on the boom having riding thereon a trolley; d. a lift cable on the trolley and adapted to lift and lower crane loads; and e. separate driving means for rotating the boom, moving the trolley, and lifting and lower a load; a lever pivoted on a pair of axes disposed normal to one another, means on each of The axes for determining a signal proportional to lever movement, and means for transmitting the determined signals to the separate driving means; wherein the lever is pivoted within a first trunnion, and said lever extends within a groove in a U-shaped portion of a second trunnion pivoted normally to said first trunnion, whereby said lever can selectively rotate both said first and second trunnions separately or simultaneously; said device having a gear segment fixed on each of the first and second trunnions; a pinion engaged with each of said segments, potentiometers adapted to be operated by rotation of said pinions, whereby electrical signals proportional to lever movement are determined, and means for returning said lever to an origin, or dead center position, including a. cams on the first and second trunnions; b. cam followers in engagement with the cams, and c. springs biasing the cam followers against the cams. 